Accurate color reproduction is essential for color display manufacturers. The goal of accurate color reproduction is to reproduce exactly the same colors on the display device as those colors are perceived by the human visual system. However, as most of the input and output devices are currently using device dependent color spaces, like RGB and YUV color spaces, to represent colors, reproducing accurate color turns out to be extremely difficult. To make the color reproduction easier, the television industry sets some color standards so that if both input device and output device comply with the standard, essentially accurate color could be reproduced. However, it is still difficult and expensive to completely comply with the color standard, even with the traditional CRT phosphors. The situation becomes more difficult as new display technologies such as LCD, DLP and PDP develop. Usually, a professional color calibration is needed to achieve better color reproduction of the high end TV displays.
In order to comply with a color standard, three points are important for display manufacturing: (1) the color accuracy of the three primary colors; (2) the black level of each primary color; and the (3) linearity of the luminance vs. driving voltage. Usually the three primary colors are fixed in the display, but the black level and luminance vs. voltage have some flexibility for calibration. The calibration professionals use so-called gray scale tracking to adjust the flexible parameters with the help of expensive instruments that can measure light chrominance and correlated color temperature. Customers who buy a high end new display need to pay extra money to have the display calibrated to obtain the best possible video quality out of the display.